CVE-2011-1795 in Chrome
Summary
by MITRE
Integer underflow in the HTMLFormElement::removeFormElement function in html/HTMLFormElement.cpp in WebCore in WebKit in Google Chrome before 11.0.696.65 allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via a crafted HTML document containing a FORM element.
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Analysis
by VulDB Data Team • 04/10/2022
The vulnerability identified as CVE-2011-1795 represents a critical integer underflow flaw within the WebKit rendering engine's HTML form processing functionality. This issue resides in the HTMLFormElement::removeFormElement function located in html/HTMLFormElement.cpp within the WebCore component of Google Chrome. The vulnerability manifests when Chrome processes malformed HTML documents containing specially crafted FORM elements, creating a scenario where integer arithmetic operations produce unexpected negative results that can corrupt memory structures and lead to application instability.
The technical exploitation of this vulnerability occurs through careful manipulation of form element removal operations where the integer underflow causes the application to attempt invalid memory access patterns. When the removeFormElement function processes a malformed FORM element, it performs arithmetic operations on integer values that, under certain conditions, result in underflow conditions. This type of vulnerability falls under CWE-191, which specifically addresses integer underflows, and represents a classic example of how improper input validation can lead to memory corruption vulnerabilities. The flaw demonstrates poor boundary checking in the form element management system where the application fails to properly validate the range of integer values before performing arithmetic operations.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable more sophisticated attack vectors. While the primary effect is application crash leading to denial of service, the underlying memory corruption characteristics suggest that remote attackers could potentially leverage this flaw for more severe consequences including arbitrary code execution. The vulnerability affects Google Chrome versions prior to 11.0.696.65, representing a significant attack surface given Chrome's widespread adoption and the ease with which malicious HTML content can be delivered through web pages, email attachments, or compromised websites. This vulnerability aligns with ATT&CK technique T1203, which covers exploitation of software vulnerabilities for privilege escalation or code execution.
Mitigation strategies for CVE-2011-1795 require immediate patch deployment to update Chrome to version 11.0.696.65 or later, which contains the necessary fixes to prevent the integer underflow condition. Additionally, organizations should implement web content filtering solutions that can detect and block suspicious HTML content containing malformed FORM elements. Browser security configurations should be enhanced to restrict form element manipulation capabilities where possible, and regular security assessments should verify that no other similar integer underflow vulnerabilities exist within the browser's rendering engine. The fix implemented by Google Chrome developers involved proper integer bounds checking and validation of form element removal operations to prevent underflow conditions. Security teams should also consider implementing network-based intrusion detection systems that can identify patterns associated with exploitation attempts of similar integer underflow vulnerabilities in web browsers.